Handholds

[martin0759]

Done with the scuppers, now on the the handholds. The poptop has both interior and exterior handhold that I have removed (taped up holes), cleaned and i am sanding to varnish. The exterior handholds have bolts going up threw the roof, threw the handholds to a nut in a counterbored hole with a teak plug. Once I pot the holes, varnish the handholds and bed with buytl tape I should be good
Where I need help is the interior handholds. They where originally screwed down threw the roof with silicone seal around the screws. I know I need to pot the holes to make sure there is no water getting into the plywood core. My question is what is the best method of sealing the screws heads? By the time I get them tight I will have worked all the sealant out by spinning the screw. Second thought was should I get rid of the screws and go with bolts with the nuts countbored into the handholds?

And no unfortunately I cannot relocate them so the bolts match, already looked at that.

Thank you for any advise.
Martin

[skipmac]

Any place you drill through the deck or cabin into the core the best thing to do is this.

Make the hole bigger than the screw or bolt.

Fill the hole with thickened epoxy.

Drill the smaller hole through the big epoxy plug.

Now if you do get a leak the water won't go into the core.

I have seen some detailed instructions on the technique somewhere but can't find it at the moment.

[martin0759]

Ship thank you, that is what I was referenceing when I referred to "potting", that is the name they to the process of sealing the core. Time consuming but pretty straightforward.

I am trying to figure out how to seal everything when the screw or bolt is going down thru the deck to an inside attachment.

Martin

[skipmac]

Doh!

Missed that, twice even.

So if I understand correctly, the interior handholds are attached by screws coming down through the cabin top or deck?

First in this situation I would lean towards through bolting. Handholds can take a lot of strain when the boat is rocking and rolling.

Are the screws flathead/countersunk or pan head? If flathead it doesn't leave much space for goop under the screw head in the countersunk hole. If not already and it doesn't look terrible or create some problem I would go with pan head or truss head. Then still use a countersink bit to make a little pocket at the top of the hole to hold more goop.

I agree spinning a screw with sealant isn't the best but I've had a couple of spots on my boat where I had no other option and still managed to get a good seal using butyl tape.

Last thing, if the previous sealant was silicone based you will need to clean the area well, probably sand it down some to get a good seal on the new install. Silicone oils from the caulk will penetrate the fiberglass and even more silicone doesn't stick well to that spot.

[martin0759]

Skip, yes currently the screws go down thru the roof.

I figured I should go with thru bolts for the strength, thanks for the confirmation.

The screws are flat heads with a lightweight stamped washer. If I countersuit the holes AMD use truss head bolts. Would there be enough sealant left after tightening them to be of any value?

How much material do I need to remove to depthwise to get rid of the silicone problem. I have seen it mentioned that it needs to be done bit never how much or how to tell.

Thank you Martin

[skipmac]

Well I'm a belt AND suspenders guy for anything even semi critical so, depending on the size of the truss head I would use a washer as well. That will give a larger bearing area and also allow a larger pocket under the washer to hold the caulk.

If you haven't seen this, here's a good how to with photos to see how the expert does it.

Re-Bedding Deck Hardware With Bed-It Butyl Tape Photo Gallery by Compass Marine How To at pbase.com

I rebedded my ports that had been caulked with silicone and had the same question. I did a trial and error to see how well I could get butyl tape to stick after sanding. First wiped the area with solvent and some goop I found that claimed to clean silicone (not sure if it really did anything). Then sanded a little and took a small ball of butyl tape and mashed it into the fiberglass to see if it would stick. I did find that sometimes the butyl wouldn't stick very well right off the bat but if I left a few hours or overnight and came back to pull it off it was stuck well.

[martin0759]

Skip, you gave me a great idea. If i drill out the washer slightly and countersink the bottom side of the washer and the potted hole both. When i install the bolt fill both with tape. To help force the butyl tape up around the bolt shank. When I tighten the bolt it should help squeeze the tape into any voids.

Thanks for the link, that is the one site that called filling the holes "potting".

Thanks
Martin